Torsion spring actuated snap action electric switch



C. W. HEATH May 18, 1965 TORSION SPRING ACTUAI'ED SNAP ACTION ELECTRIC SWITCH Filed March 11, 1963 INVENTOR 6'1. HRENGE WILLHIY 507/1, 8 Y MM ATTORNEY United States Patent 3,184,561 TORSION SPRING ACTUATED SNAP ACTION ELECTRIC SWITCH Clarence Willans Heath, Bleasby, Nottingham, England, assignor to United-Carr Incorporated, Boston, Mass, a corporation of Delaware Filed Mar. 11, 1963, Ser. No. 264,406 Claims priority, application Great Britain, July 13, 1962, 27,089/ 62 3 Claims. (Cl. 20067) This invention relates to electric switches.

According to the present invention, an electric switch comprises a base having a stationary contact mounted thereon, a movable contact and an actuating element for eifecting the movement of the movable contact relative to the stationary contact, the actu ating element including a first arm pivotally mounted on the base and carrying the movable contact, a second arm engageable by a switch actuating member, and resilient means connecting adjacent ends of the said arms, the arrangement being such that the operation of the switch operating member will cause the resilient means to be stressed or tensioned so as to store up energy which is released after a pre-determined movement of the switch operating member and thereby effect a rapid pivotal movement of the first mentioned arm to move the movable contact relative to the stationary contact to open or close the switch.

The movable contact may be mounted on the free end of the first arm which is pivotally supported on the base adjacent its opposite end.

According to one arrangement, the first and second arms and the resilient means comprise integral portions of a strip of spring metal, the resilient means taking the form of an arcuate shaped portion of the strip whose opposite ends are integrally connected to the adjacent ends of the said arms.

The first arm portion of the strip may be supported on a contact blade which forms a fulcrum point about which the said arm is adapted to be pivoted, the second arm extending over the first arm in spaced relation thereto and being formed with a notch or recess for engagement by a lug carried by the said switch operating memher.

To enable the invention to be fully understood, it will now be described by way of example, with reference to the accompanying drawing which is a sectional side view of an electrical switch according to one embodiment of the invention.

As shown in the accompanying drawing, the switch which is a single pole make and break switch, comprises a base 1, having a stationary contact 2 connected by a rivet 3 to a wiring terminal 4. A second wiring terminal is provided secured to the base by a rivet 5 and including a wire attaching portion 6 and a contact blade 7 extending through a hole in the base so as to project at right angles from the upper face.

A housing 8 is mounted on the base and provided with a metal cover 9 formed with integral resilient tongues 10 shaped for snapping engagement in an aperture in a support with which the switch is to be assembled. A switch operating member is provided including a base 3,l84,5fil Patented May 18, 1965 "Ice 11 pivotally mounted by means of pins 12 in opposed side walls of the housing 8, an actuating ing 13 depending from the base and a button 14 extending outwardly through the cover.

A switch actuating element is provided including a first arm 15 carrying the contact 16 at its free end, a second arm 17 overlying the first arm and connected thereto by a resilient arcuate shaped portion 18 of generally C shape. Intermediate its ends, the arm 15 is pivotally supported on the blade contact 7 which serves as a fulcrum for the actuating element. The arm 17 is bent adjacent its free end to provide a recess for receiving the lug 13.

As illustrated in the accompanying drawing, the switch is in closed position with the contact 16 engaging the contact 2. To open the switch, the button 14 is depressed to pivot the base 11 so that the log 13 will move the arm 17 downwardly. During the initial part of this movement, the arcuate portion 18 will be under compression and store up energy which will be released after a pre-determined movement of the arm 17 to effect a rapid pivotal movement of the arm 15 so as to lift the contact 16 away from the stationary contact 2. The contacts are held in disengaged position only so long as button 14 is depressed and immediately it is released the arm 15 will be returned to the position indicated in FIGURE 1.

The circuit to the contacts is completed through the wiring terminals 4 and 6, the latter being connected through the contact blade 7 to the arm 15.

If desired, the stationary contact may be located in such position, for example, above the contact 16, so that the contacts are normally out of engagement and are brought into engagement to close the switch only when the button 14 is depressed.

Switches according to the present invention are particularly applicable for cases where a circuit is to be temporarily opened or closed, and one example is in connection with switches adapted to be operated on the opening of a door or the like such as the door of a refrigerator.

I claim:

1. An electrical switch including a base having first and second stationary contacts mounted thereon, a movable contact, a one piece actuating element for effecting the movement of said movable contact out of engagement with said first stationary contact and a switch operating member engaging said actuating element, the former comprising a first arm pivotally supported by said second stationary contact acting as a fulcrum, and having said movable contact afiixed to a free end thereof, a second arm in spaced superposed relation to said first arm and said base and having one end engaging said switch operating member and another end connected to said first arm by a resilient arcuate shaped portion, whereby depression of said switch operating member will cause said resilient arcuate portion to be placed in tension so as to store potential energy which is released after a predetermined movement of said switch operating member thereby efiecting a rapid pivotal movement of said first arm about said second stationary contact and a disengagement of said movable contact and said first stationary contact.

. 3 4;. 2. An electrical switch according to claim 1 wherein 7 References Cited by the Examiner a release of said switch operating member causes a rapid, UNITED STATES PATENTS reverse pivotal movement of said first arm about said second stationary contact to effect a re-engagement of 2,758,171 8/56 h 200 67 said movable and first stationary contacts. 5 2809247 10/57 Wmtle 200 67 3. An electrical switch according to claim 1 wherein 3098903 7/63 Anderson f 200-67 said first arm of said actuating element has a transverse FOREIGN PATENTS arch adjacent said resilient arcuate shaped portion pro- 1150552 3/57 France viding a concave bearing surface for pivotal movement 1 252 9 7 4 1 Rama of said element about said second stationary contact act- 10 ing as a fulcrum. BERNARD A. GILHEANY, Primary Examiner. 

1. AN ELECTRICAL SWITCH INCLUDING A BASE HAVING FIRST AND SECOND STATIONARY CONTACTS MOUNTED THEREON, A MOVABLE CONTACT, A ONE PIECE ACTUATING ELEMENT FOR EFFECTING THE MOVEMENT OF SAID MOVABLE CONTACT OUT OF ENGAGEMENT WITH SAID FIRST STATIONARY CONTACT AND A SWITCH OPERATING MEMBER ENGAGING SAID ACTUATING ELEMENT, THE FORMER COMPRISING A FIRST ARM PIVOTALLY SUPPORTED BY SAID SECOND STATIONARY CONTACT ACTION AS A FULCRUM, AND HAVING SAID MOVABLE CONTACT AFFIXED TO A FREE END THEREOF, A SECOND ARM IN SPACED SUPERPOSED RELATION TO SAID FIRST ARM AND SAID BASE AND HAVING ONE END ENGAGING SAID SWITCH OPERATING MEMBER AND ANOTHER END CONNECTED TO SAID FIRST ARM BY A RESILIENT ARCUATE SHAPED PORTION, WHEREBY DEPRESSION OF SAID SWITCH OPERATING MEMBER WILL CAUSE SAID RESILIENT ARCUATE PORTION TO BE PLACED IN TENSION SO AS TO STORE POTENTIAL ENERGY WHICH IS RELEASED AFTER A PREDETERMINED MOVEMENT OF SAID SWITCH OPERATING MEMBER THEREBY EFFECTING A RAPID PIVOTAL MOVEMENT OF SAID FIRST ARM ABOUT SAID SECOND STATIONARY CONTACT AND A DISENGAGEMENT OF SAID MOVABLE CONTACT AND SAID FIRST STATIONARY CONTACT. 